TWI660628B - Method for playback synchronization of media among devices - Google Patents

Abstract

In the method for synchronously playing media among multiple devices provided by the present invention, a first device is set as a broadcast terminal and a plurality of other second devices are set as receivers in a plurality of playback devices. When a plurality of playback devices complete real-time time correction and play a piece of media data, the first device monitors the gap between the media time difference of the media material when the first device plays and the real-time time difference of the system. When the difference exceeds the allowable time , The first device broadcasts the current media time and real-time time information to each second device, and each second device uses the received message as a new starting playback point to adjust the next media data. The playing time, so that each second device can keep the image playing synchronously with the first device.

Description

Method for synchronously playing media among multiple devices

The present invention relates to a method for playing media, and more particularly, to a method for playing media simultaneously between multiple devices.

Multiple media playback devices play the same audio and video media at the same time, which has a wide range of applications, such as television walls, advertising walls, display walls, etc. The use of multiple displays to stitch images allows the playback of images to break through the limitations of the existing display size, and Large playback size renders. In this field where multiple displays are used for splicing (each display only plays partial images of audiovisual media), or multiple displays are playing the same audiovisual media (displays can also be stitched together or scattered in different locations), One of the most critical technologies is to maintain the image synchronization between the displays.

Generally speaking, the media data transmitted to each display has its own media time, and each display also has its own real-time clock (RTC) or RTC time. When the real-time time of all displays is corrected to each other and the data content of the same media time in the media material is played at the same time point (real-time time), the displays can produce synchronized playback results with each other. Conversely, if the media data content played by one or more displays at the same time point is different from the media time content of the media data content of other displays, a problem of image out-of-sync will occur. However, when the media time difference between any two monitors that are out of sync is large to a certain extent, the image difference presented by the out of sync will be perceived by the viewer and lose the purpose of synchronized playback by the multimedia playback device.

Therefore, the present invention provides a method for synchronously playing media among multiple devices to solve the above-mentioned problems.

The method for synchronously playing media among multiple devices provided by an embodiment of the present invention includes a first device and a plurality of second devices in a plurality of playback devices. When the plurality of playback devices play a media material, the first The device has a first real-time time and a first media time to play the media material, and each second device has a second real-time time and a second media time to play the media material, and the method includes: according to the first The real-time time corrects the second real-time time; when the media material is played, the first device transmits the first real-time time and the first media time to the plurality of second devices; each of the second devices is based on the received The first real-time time and the first media time, and the second real-time time of the second device to obtain a synchronized media time; and each of the second devices and the first media time according to the synchronized media time and the second media time. A device synchronizes to play the media material.

In the method provided in the embodiment of the present invention, the correction of the second real-time time according to the first real-time time is performed by the first device to correct the second real-time time of the plurality of second devices or by each of the second devices. Correct the second real-time of each second device according to the first real-time.

In the method provided by the embodiment of the present invention, when playing the media data, when the difference between a first media interval and a first real-time interval of the first device is greater than a preset value, the first device will The first real-time time and the first media time are transmitted to the plurality of second devices, wherein the first media interval is the media time between the first media time and the first device ’s latest transmission to the plurality of second devices Interval (Mn-Mm), the first real-time interval is the interval (Tn-Tm) between the first real-time time and the real-time time that the first device last transmitted to the plurality of second devices.

In the method provided by the embodiment of the present invention, the synchronized media time is a difference between the second real-time time and the first real-time time plus the first media time.

In the method provided by the embodiment of the present invention, each of the second devices synchronizing with the first device to play the media data according to the synchronized media time and the second media time includes the steps of comparing each second device A synchronization action is performed on the synchronized media time and the second media time of the second device according to a comparison result.

In the method provided by the embodiment of the present invention, when the synchronized media time is greater than the second media time, the synchronization action is that the second device fast-forwards to the synchronized media time to play the media material or the second device Play the media data at the synchronized media time directly.

In the method provided by the embodiment of the present invention, when the synchronized media time is less than the second media time, the synchronization action is that the second device reverses to the synchronized media time to play the media data or the second device directly Play the media data at the synchronized media time.

In the method provided by the embodiment of the present invention, wherein the media data is image data, the method further includes the step of: the first device synchronizes the image and sound with respect to the media data.

In the method provided by the embodiment of the present invention, the plurality of second devices are directly wirelessly connected to the first device or the first device and the plurality of second devices are connected to each other through a wireless access device.

The media synchronization method provided by the present invention utilizes the correction of media time and real-time time inside the playback device to simplify the installation and playback of multiple devices. It is suitable for solving playback errors caused by the device itself or external variations, and minimizes the use of The number of wireless packet broadcasts reaches the expected playback performance. No additional equipment is needed to participate in the timing control of synchronous playback, that is, the synchronous playback of images between devices can be achieved wirelessly. It has the advantages of simplicity and flexibility in installation.

Certain terms are used in the description and the scope of subsequent patent applications to refer to specific elements. Those with ordinary knowledge in the field should understand that manufacturers may use different terms to refer to the same component. The scope of this specification and subsequent patent applications does not take the difference in names as a way to distinguish components, but rather uses the difference in functions of components as a criterion for distinguishing components. "Inclusion" mentioned throughout the specification and subsequent claims is an open-ended term and should be interpreted as "including but not limited to." In addition, the term "coupled" or "connected" includes any direct and indirect means of electrical or structural connection. Therefore, if a first device is described as being coupled / connected to a second device, it means that the first device can be electrically / structured directly connected to the second device, or indirectly electrically / structured through other devices or connection means. To the second device.

Please refer to FIG. 1. FIG. 1 is a schematic diagram of a media playback system used in a method for performing media synchronization playback among multiple devices according to the present invention. The media playback system 10 is composed of multiple playback devices (or a wireless access device 3). The multiple playback devices include a first device 1 and a plurality of second devices 2. In one embodiment, a plurality of playback devices The second device 2 is directly connected to the first device 1 wirelessly. In another embodiment, the first device 1 and the plurality of second devices 2 can also communicate with each other through the wireless access device 3. The media playback system 10 can simultaneously play multimedia content containing only video or both video and audio on multiple playback devices. The first device 1 is set as a broadcast terminal, and the other multiple second devices 2 are set. Set to the receiver. The method for synchronously playing media provided by the present invention can be used in a large-scale splicing or multi-display media playback system such as a television wall, an advertising wall, and a display wall. A smart display or a general display with a smart set-top box can be used as media The playback device in the playback system 10 performs precise synchronization of sound and video.

Please refer to FIG. 2 together. FIG. 2 is a schematic diagram of a media device played by a playback device in a media playback system. The media data 100 can be stored on the first device 1 and transmitted to the second device 2 (for simplicity, only one second device 2 is used for illustration in the second figure) or other media hosts (not shown) by cable Or wirelessly (such as through the wireless access device 3 or the cloud platform 4 in FIG. 1) to the first device 1 and the second device 2 respectively for synchronous playback. The real-time time (RTC time) of the first device 1 and the plurality of second devices 2 are represented by black points Tm, Tn, Tr ... ) Are represented by Mm, Mn, Mr ..., respectively. When the real-time time between the first device 1 and the plurality of second devices 2 is corrected to each other and the data content of the same media time (or the media within the allowable error time) is played at the same real-time time Time data content), all playback devices can produce synchronized playback results with each other.

Please refer to FIG. 3. FIG. 3 is a flowchart of a method 200 for synchronously playing media among multiple devices provided by the present invention. The steps are as follows:

Step 210: Set up a media playback system.

Step 220: Correct the real-time time of the plurality of playback devices;

Step 230: the playback device starts playing media data at a real time point;

Step 240: The first device monitors the gap between the first media interval and the first real-time interval in real time, and transmits the first real-time time and the first media time to the plurality of second devices when the gap is greater than a preset value;

Step 250: the plurality of second devices generate a synchronized media time;

Step 260: Compare the synchronized media time with the second media time, and perform synchronization to play the media data accordingly.

Please refer to Figure 1 and Figure 2 together. In a media playback system 10 having multiple playback devices, each playback device has its own system time or real-time time. Therefore, in step 210, the present invention first sets up a media playback system 10. The specific method may include: Among the plurality of playback devices of the playback system 10, one of the playback devices is set as the first device 1 as a broadcast terminal, and the other playback devices are set as the second device 2 as a receiver, and the first device 1 is directed to the media data to be played 100 Synchronizes video and audio. Specifically, for media material 100 having both sound and video, in one embodiment, the sound of the media material 100 is output by the first device 1 (or a speaker device connected to the first device 1), and the media The audio and video synchronization of the data 100 is completed by the first device 1 in the first device 1.

Then, in step 220, the real-time time of each playback device is corrected to synchronize with each other. For example, the first device 1 has a first real-time time RTC1, and the plurality of second devices 2 each have a second real-time time RTC2, and according to the first real-time time. RTC1 corrects the second real-time time RTC2. In one embodiment, after all the playback devices are connected to the wireless access device 3, the first device 1 periodically sends a correction instruction to correct the second real-time time RTC2 of each second device 2. In another embodiment, In addition, the first device 1 can also enable its own wireless sharing function. After each second device 2 is connected to the first device 1, the second device 2 performs automatic real-time time correction to correct it according to the first real-time time RTC1. A second real-time time RTC2 within the second device 2. In addition, it should be noted that multiple second devices 2 use the same second real-time time RTC2 to distinguish them from the first real-time time RTC1 of the first device 1. Before step 220, multiple second devices 2 The device 2 may make the respective second real-time time RTC2 different due to various factors.

After the real-time times of all the playback devices are synchronized, then in step 230, the first device 1 transmits the real-time time point at which the media material 100 starts to play, and all the playback devices start to play the media material 100 at the common real-time time point. When the first device 1 and the multiple second devices 2 are playing the media material 100, due to the hardware processing capabilities of each playback device and the differences in their respective hardware and software environments, the media time in the playback device and the real-time time The gap between the two has begun to develop, and the gaps generated by each playback device are also different. When the gap between the media time of the first device 1 and the progress of the real-time time is too large, it means that the media material 100 in the first device 1 is played too fast (the media time is performed faster than the real-time time) or played too slowly ( The media time is slower than the real-time time). At this time, it is necessary to coordinate other second device 2 to correct the content played by the media material 100.

In step 240, the first device 1 will immediately monitor the difference Δ between a first media interval and a first real-time interval in the first device 1. Here, the first media interval is defined as the time when the first device 1 is monitoring. The interval (Mn-Mm) between the first media time Mn of the first device 1 and the media time Mm most recently transmitted from the first device 1 to the plurality of second devices 2, and the first real-time interval is defined as the first time when the first device 1 is monitoring the current The interval (Tn-Tm) between the real-time time Tn and the real-time time Tm most recently transmitted from the first device 1 to the plurality of second devices 2, and the gap Δ = (Mn-Mm)-(Tn-Tm). The aforementioned media time Mm and real-time Tm of the latest transmission to the second device 2 represent the time when the first device 1 and the second device 2 were synchronized with each other (the media time of each playback device after this time point) Start at different speeds and start to differ from the real-time time), and the initial media time Mm and real-time time Tm are the media time at the real-time point in time when the first device 1 starts transmitting the media material 100 in step 230 Mm and real time Tm.

In addition, in one embodiment, the variation of the gap Δ usually depends on the internal hardware and software or the external environment of the first device 1, and the role of the first device 1 in synchronizing the audio and video and playing the sound also affects the gap Δ. Range of change.

In an embodiment, when the gap Δ is greater than a preset value, for example, 16 milliseconds (if the media data 100 is a 60 fps playback format, 16 milliseconds is the time to play a frame), the first device 1 monitors The current first real-time time Tn and the first media time Mn are transmitted to each second device 2 respectively, that is, the first device 1 broadcasts the media information of the current playback progress to other second devices 2 so that the second device 2 2 Perform calibration.

For example, each second device 2 also has a second media time Mn ′ when playing the media material 100 (in addition, the media time Mm ′ of a second device 2 in FIG. 2 is also the second Device 2 was synchronized with the first device 1 and corrected the media time), when a second device 2 received the first device at the real time Tp (later than the first real time Tn and the second real time Tn) 1 when the correction data (ie, the first real-time Tn and the first media time Mn) is transmitted, the content of the media material 100 that should be played at the current second real-time Tr (which should be the same as the first device 1) Synchronized with the first device 1) has a synchronized media time Ms, where the synchronized media time Ms is the difference between the second real time Tr and the received first real time Tn plus the received first media time Mn, also That is, Ms = Mn + (Tr-Tn). In other words, after each second device 2 obtains the message from the first device 1, it regards it as a new starting playback time point, and adjusts the playback time of the next content of the media material 100.

Then each second device 2 compares according to the obtained synchronized media time Ms and the second media time Mr ′ that each second device 2 originally wants to play at the current second real time Tr, and executes a corresponding one according to the comparison result. The synchronization action is to synchronize with the first device 1 to play the media material 100, such as step 260. In one embodiment, each second device 2 originally wants to play the second media time Mr at the current second real-time time Tr. The content of 'is actually stored in a buffer in each second device 2 and is waiting to be played. For example, when the synchronized media time Ms is greater than the second media time Mr ', it means that the playback speed of the first device 1 is faster than a certain second device 2, so the synchronization action performed by the second device 2 can be fast forward to The synchronized media time Ms is used to play the content of the media material 100 or directly jump to play the content of the media material 100 (discard the outdated data content in the buffer). When the synchronized media time Ms is less than the second media time Mr ', it means that the playback speed of the first device 1 is slower than that of a second device 2. Therefore, the synchronization action performed by the second device 2 may be reversed to the synchronized media time Ms to Play the content of the media material 100 or directly jump to play the content of the media material 100 with the synchronized media time Ms.

After the image synchronization of the first device 1 and the second devices 2 is completed at a certain point in the present invention, steps 240 to 260 are repeatedly performed, so that whenever the playback speed of the first device 1 is too fast or too slow, it is performed. The synchronization step in the present invention keeps the first device 1 and other second devices 2 in a state of image synchronization at any time.

In the method for synchronously playing media among multiple devices provided by the present invention, a first device is set as a broadcast terminal and a plurality of other second devices are set as receivers in a plurality of playback devices. When a plurality of playback devices complete real-time time correction and play a piece of media data, the first device monitors the gap between the media time difference of the media material when the first device plays and the real-time time difference of the system. When the difference exceeds the allowable time , The first device broadcasts the current media time and real-time time information to each second device, and each second device uses the received message as a new starting playback point to adjust the next media data. The playing time, so that each second device can keep the image playing synchronously with the first device. The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the scope of patent application of the present invention shall fall within the scope of the present invention.

10‧‧‧Media playback system

1‧‧‧ the first equipment

2‧‧‧Second Equipment

3‧‧‧Wireless Access Device

100‧‧‧ Media Information

4‧‧‧ Cloud Platform

200‧‧‧Media synchronous playback method

210-260‧‧‧step

FIG. 1 is a functional block diagram of a three-dimensional object scanning device according to the present invention. FIG. 2 is a schematic diagram of a media device played by a playback device in a media playback system. FIG. 3 is a flowchart of a method for synchronously playing media among multiple devices provided by the present invention.

Claims (10)

A method for synchronously playing media among multiple devices includes a first device and a plurality of second devices in a plurality of playback devices. When the plurality of playback devices play a media material, the first device has a first real-time time And a first media time for playing the media data, each second device having a second real-time time and a second media time for playing the media data, the method includes: correcting the second real-time based on the first real-time time Time; when playing the media material, when the difference between a first media interval and a first real-time interval of the first device is greater than a preset value, the first device sets the first real-time time and the first media Time transmission to the plurality of second devices, wherein the first media interval is an interval (Mn-Mm) between the first media time and the media time that the first device transmitted to the plurality of second devices last, the first media interval A real-time interval is the interval (Tn-Tm) between the first real-time time and the real-time time that the first device last transmitted to the plurality of second devices; each second device receives The first real-time time and the first media time, and the second real-time time of the second device to obtain a synchronized media time; and each second device communicates with the second media time according to the synchronized media time and the second media time. The first device performs synchronization to play the media material. The method according to claim 1, wherein the correction of the second real-time time according to the first real-time time is the correction of the second real-time time of the plurality of second devices by the first device or each of the second devices according to the The first real-time time corrects the second real-time time of each of the second devices. The method according to claim 1, wherein the synchronized media time is a difference between the second real-time time and the first real-time time plus the first media time. The method of claim 1, wherein each of the second devices synchronizes with the first device to play the media data according to the synchronized media time and the second media time includes the steps of each of the second devices comparing the synchronization Perform a synchronization action on the media time and the second media time of the second device according to the comparison result. The method according to claim 4, wherein when the synchronized media time is greater than the second media time, the synchronization action is that the second device fast-forwards to the synchronized media time to play the media data. The method according to claim 4, wherein when the synchronized media time is greater than the second media time, the synchronization action is that the second device directly plays the media data of the synchronized media time. The method according to claim 4, wherein when the synchronized media time is less than the second media time, the synchronization action is that the second device reverses to the synchronized media time to play the media material. The method according to claim 4, wherein when the synchronized media time is less than the second media time, the synchronization action is that the second device directly plays the media data of the synchronized media time. The method according to claim 1, wherein the media data is video data, and the method further comprises the step of: the first device synchronizes the video and sound with respect to the media data. The method according to claim 1, wherein the plurality of second devices are directly wirelessly connected to the first device or the first device and the plurality of second devices are connected to each other through a wireless access device.